Sandbox URL : https://sandbox.2checkout.com/checkout/purchase
Live URL : https://www.2checkout.com/checkout/purchase
<form method="post" action="https://www.2checkout.com/checkout/purchase" id="pay_checkout_now">
<input type="hidden" value="202356803" name="sid">
<input type="hidden" value="2CO" name="mode">
<input type="hidden" value="N" name="li_0_tangible">
<input type="hidden" value="product" name="li_0_type">
<input type="hidden" value="1" name="li_0_quantity">
<input type="hidden" value="Bill for order #5772" name="li_0_name" id="twocheck_item_name">
<input type="hidden" value="56.00" name="li_0_price" id="twocheck_amount">
<input type="hidden" value="5772" name="li_0_product_id" id="twocheck_item_number">
<input type="hidden" value="return url of your website" name="x_receipt_link_url" id="twocheck_return">
<input type="submit" value="Pay with 2Checkout" class="coloredbtn_inq pay2cc_inq" name="submit_twocheck" id="paycheckout">
</form>
Read more about here https://www.2checkout.com/developers
Live URL : https://www.2checkout.com/checkout/purchase
<form method="post" action="https://www.2checkout.com/checkout/purchase" id="pay_checkout_now">
<input type="hidden" value="202356803" name="sid">
<input type="hidden" value="2CO" name="mode">
<input type="hidden" value="N" name="li_0_tangible">
<input type="hidden" value="product" name="li_0_type">
<input type="hidden" value="1" name="li_0_quantity">
<input type="hidden" value="Bill for order #5772" name="li_0_name" id="twocheck_item_name">
<input type="hidden" value="56.00" name="li_0_price" id="twocheck_amount">
<input type="hidden" value="5772" name="li_0_product_id" id="twocheck_item_number">
<input type="hidden" value="return url of your website" name="x_receipt_link_url" id="twocheck_return">
<input type="submit" value="Pay with 2Checkout" class="coloredbtn_inq pay2cc_inq" name="submit_twocheck" id="paycheckout">
</form>
Read more about here https://www.2checkout.com/developers